Sunday, 28 October 2012

Igniting interest in science

Great day out in Nottingham yesterday.  It's always fun to be a shameless tourist but the highlight was not one of the usual sights (though I did enjoy Ye Olde Trip to Jerusalem) but, instead, something claiming to be The World's 1st Science Pop-up Shop.

A group called Ignite! had taken over an empty unit in the Broadmarsh shopping centre.  SG and I wandered in off the street and found a bunch of enthusiastic students, teachers and other volunteers sharing their passion for all kinds of science to curious passersby.

Plenty of parents and children on half-term stopped to check out an eclectic mix of experiments and demonstrations, focused on pointing out the amazing phenomena of everyday life.  Did you know that if you whip Marmite it goes white?  Or that if you put your thumb over a straw you can stab it straight through a potato?

The Ignite! folks were also joined by people from creative collective Hackspace, who were letting kids loose with soldering irons - I had a go and even got to make a flashing robot badge.

The walls and floor of the shop were decorated with fun facts and quizzes like the one on the left (see below for answer),which were arousing plenty of discussion among visitors.

Of course it's not a new idea to strip all the off-putting formulae and unhelpful abstractions out of science, and remove the distinctions between different scientific disciplines.  (It reminded me of many happy childhood visits to the Science Museum's basement "Launch Pad".)  What was great was to see it sandwiched in among Poundland, Argos and Wimpy.

The pop-up shop is a four-week project.  Could it work in the longer term?  It would be hard to keep fresh - they'd need to keep changing the decoration and activities if they wanted people to come back for repeat visits.  I guess they're getting the space rent-free too, which is doable with so many recession-hit units standing empty, but might not be possible indefinitely.  On the other hand, if we're all shopping online and in malls, and retailers are abandoning city centres, maybe this is the future of the high-street experience.  Saturday afternoon in town for coffee and chemistry, anyone?

(Apparently frogs' bones grow in visible rings, just like trees - so you can tell their age by cutting them open.  But bad luck on the frog...)

Monday, 22 October 2012

A Spanish "Encyglobedia"

Just published a new article on the Whipple Museum's "Explore Collections" site.  Here it is:

Not about an astrolabe this time, but a curious globe - here's a picture:

Sunday, 21 October 2012

How I found King Arthur's Round Table

I've just started a research project focusing on a medieval manuscript, The Equatorie of the Planetis.  This manuscript describes the construction and use of a curious astronomical instrument, and my previous post was about the first stages in my attempt to reconstruct that instrument, in order to better understand the manuscript.

I'm still working on that, and will write all about the fun I had trying to divide a three-foot circle into 360 equal degrees very soon.  Before that, though, here's a tale of intrigue to liven up your weekend...

I'm not the first person to study The Equatorie of the Planetis, or indeed to make a replica of it.  The great historian of science Derek de Solla Price researched it for his (second) PhD in the 1950s, and published an edition of the manuscript, complete with detailed commentaries in which, among other topics, he put forward his argument that the manuscript was by Geoffrey Chaucer, and indeed had been written in Chaucer's own handwriting.  Price was friends with the Nobel Prize-winning physicist Lawrence Bragg, who by the 1950s was running Cambridge University's Cavendish Laboratory, and Bragg arranged for the Cavendish technicians to make a full-size replica of the Equatorie.

I had read that Bragg's gift was "to be hung in a place of honour on the end wall of the big room" of the fabulous Whipple Museum of the History of Science in Cambridge.*  But none of the Whipple's current staff was aware it existed, let alone where it might be now; and the quote above could conceivably have meant that the equatorium was intended to be hung in the Whipple, but never actually made it there.  So I wasn't very confident, but decided I'd have a go at finding out what happened to the mysterious equatorium.  I thought I might at least be able to find some of the paperwork connected with its production at the Cavendish, and maybe some hints about its fate.

I made an appointment to check out the Whipple's archives and, when I met up with the archivists, explained to them what the equatorium was and what the replica might have looked like: a six-foot wooden circle with a similarly-sized brass ring attached.  They looked at each other for a moment, then one said "do you think it might look a bit like this?"  On the computer screen they showed me a museum database record for an unidentified object.  Although I'd obviously never seen the Equatorie, I instantly recognised from the photo that this mystery object must be Price's replica.  The object was described accurately in the database record but the cataloguer, not knowing precisely what it was, had apparently struggled to come up with a title for the record.  So this six-foot wooden circle had been officially named King Arthur's Table!

We went out to the stores and, as carefully as we could given its size, wheeled it out from its resting-place behind a large storage cupboard.  It was dusty and a bit scratched, but unmistakable.

Dining space for about eight guests

I'm now gradually piecing together the story of this remarkable item.  It was made in 1952 and soon afterwards given to the museum, where it hung happily for a few years.  However, as both the museum collection and the Cambridge University Department of History and Philosophy of Science expanded, it seems there was not room to display it, or to store it on the premises.  It was moved to a storage facility for about a decade.  In the 1970s, the Whipple's curator wanted to move some items out of that facility, but, he told me, the stairs were so rickety that no contractor would take the job.  So he did it all himself.  Unfortunately, the Equatorie was too big to fit in his car so it lingered in the same storage facility for another few years!  Finally it was moved into the Whipple's current store in the 1980s.

Hopefully it will soon be back on display in the Whipple Museum.  However, it may have to lose its splendid Arthurian name, which would be a slight pity as it does capture the romance of the Whipple's early years (not to mention my own quest).  I think I know why they called it Camelot now...

(* The quote is from the Whipple's 60th anniversary publication, an excellent collection of essays on a range of subjects associated with the museum.)

Monday, 15 October 2012

My weekend as a medieval craftsman

With a free weekend, and fine autumn weather forecast, it seemed a good time to try making my own planetary equatorium.

I'm studying a manuscript called The Equatorie of the Planetis, which belongs to Peterhouse, Cambridge.  Much more about that in future posts; for now it's enough to say that it's a fourteenth-century instruction manual for the construction and use of a planetary equatorium, a device to compute the position of the planets.
Helpful handyman hints from our Swedish friends

Now, I'm no DIY expert, but I pride myself on being able to follow Ikea instructions without breaking anything, or myself, or having to call them for help (see right).  So I thought I'd have a go at following the instructions in "my" manuscript, and making my own equatorium.

This was not just an excuse to buy some new tools and hang out in the garden on a sunny(ish) afternoon; I was also trying to understand some of the practical issues involved in making a medieval instrument: the choices, the difficulties and perhaps the pleasures, too.

So on Saturday afternoon I headed down to Homebase and bought myself an 8 x 4-foot sheet of 6mm MDF, as well as some upholstery nails, two balls of twine, a coping saw and three rasps (I only wanted one, but it was a choice between a three-pack at Homebase and a nine-pack at B&Q...).  The friendly guys at Homebase kindly cut my board in half, and then chopped 11 inches off each half, leaving me with two large not-quite-squares, and two useful off-cuts.

Task #1: make a pair of compasses capable of drawing a three-foot circle.  This wasn't too difficult once I'd realised that they only needed to span the 18-inch radius, not the full 3-feet diameter.  (They appear on the blue towel in the second picture below.)

Task #2: draw the big circle and then cut it out of my squarish bit of MDF (twice).  Now, you may be thinking that three feet in diameter (that's 91.4 cm to those of you in civilised countries) is rather large for an astronomical instrument (though perhaps not by the standards of the Square Kilometre Array).  In fact, the original instructions call for a full six feet of circular precision, so my reproduction is a humble half-size replica.  (More about the issue of scale in future posts.)

Cutting out the circles, with appropriate canine supervision
 At this point I realised that sawing in precise circles is actually quite hard.  Granted, your medieval craftsman might have had years to hone his art (and probably had a better workbench than mine - a toolbox, if you're wondering), but then my saw is probably sharper than his.  And I'm not sure when MDF was invented, but I guess he wouldn't have had the luxury of starting with a slim, smooth, knot-free sheet of board, either.

Task #3: cut out a smaller circle inside one of the larger ones, to leave a one-inch wide ring of wood.  This "epicicle", as it's named in the manuscript (not to be confused with the epicycle of Ptolemaic theory), is supposed to be made of metal, but I'm sticking with MDF for now.  The instructions call for a bar to be soldered across the middle, but I just cut out two semicircles, leaving a half-inch strip intact.

(The picture above left shows me marking out the semicircles by the light of a handy headtorch; you'll see I tried it out in paper first, on a 1cm:4" scale.)

Unfortunately (a) my sawing wasn't very straight, and (b) a three-foot-long, half-inch-wide, six-millimetre-thick strip of MDF is not very strong.  Never mind, there's nothing a bit of gaffer tap and some strategic rasping can't fix.  (What those medieval craftsmen did without gaffer tape, I have no idea.)

 Task #4: Make a "label" [pointer] for my epicicle.  This is also supposed to be made of metal (the author specifies latoun, i.e. brass), but, you guessed it, I'm sticking with MDF.  The label is a pointer, a full three feet in length, which is fixed to the centre of the epicicle and spins round (that's what the upholstery nails were for).  As you'll see in the photo (right), the label has a little kink in the middle, as is traditional (see below, from a fourteenth-century astrolabe at the fantastic Whipple Museum).

So, after all that, I now have a lovely smooth three-foot disc, which is the face of my equatorium, and a similarly sized epicicle, complete with revolving label (see below).  Now all I need to do is to precisely mark out the zodiac signs, degrees and minutes round the outside; as well as the centre of the deferent circle and the equant point for each planet.

More about all that in a future post.  Check back here if you want to know more, or to find out why I bought those two balls of twine!

(Thanks to my wonderful housemate for some of the photos.)